How to render picture as 4 mega pixels?
one megapixel is one million pixels. Make the area of your picture equal 4 million pixels
The dimension for a 4:3 ratio would be 2309 x 1732 with 4 megapixels, so set width to 2309 and height 1732
if you dont know how to set dimensions use the amazing google recource... thats how i answered you... with https://www.scantips.com/mpixels.html